July 2010

A flurry of email activity at the start of the month before heading north to Orkney.  We were able to publicise the success of National Insect Week in the local Tiree paper, An Tirisdeach, and also follow up on an intriguing project by the Macaulay Institute, who are resurveying areas of machair that were looked at in the 1970s.  There is the chance to survey great yellow bumblebee numbers in relation to these plant surveys, which could indicate preferred management options for bees, and – very tentatively – suggest what possible impact on bee numbers any changes in vegetation and land use over the past 30+ years may have had.

I broke my journey north at a few places before catching the evening ferry, looking at the availability of spring flowers for great yellow bumblebees.  Thankfully, after a long day, I didn’t have far to go to find the B&B (The Inn at St Mary’s, Holm) which was wonderful.  I took a short walk before breakfast on the opposite side of the road where there was perhaps a total area of red clover patches totalling perhaps 20m² in an area of 100m². Remarkably, there were four great yellow bumblebee queens here (one was rather small), three of which had collected pollen!  The numbers of great yellow bumblebees certainly do seem to have increased on Orkney, probably due to a combination of good weather and beneficial management being carried out by farmers there. 

One of my reasons to visit now was to check the progress of a small number of ‘pollen & nectar’ mixes using agricultural legumes.  Three of the five sites had done well, and all of these had great yellow bumblebees.  At one of these sites, hosted by Dick Matson, we also had a quick look at bees in the garden, at Dick’s suggestion.  I looked at a patch of Geranium where there was a slow-moving bumblebee and did something of a double take – surely this is a Barbut’s cuckoo bumblebee?!  It looked just like the ones I saw with Pippa in May, with a slightly dingy yellow ‘collar’.  Catching the bee allowed us to see the distinctive ridges on the underside to confirm that this was indeed Bombus barbutellus, a rare and localised species in Scotland – the nearest records to Orkney are from Aberdeen!  John Crossley circulated the information and remarkably two more females were seen in July, another on Mainland Orkney and one on Egilsay.  It seems there are some older records from Orkney, and a photo of a good candidate was taken the year before.

I also attended an Open Day run by the Scottish Agricultural College concerning the use of clover in silage (see photo of Luing cattle, photo courtesy of Graham Scott).  The use of red clover in particular has increased, and young cattle can put on nearly 1kg a day on this rich diet!  I also visited a couple of farms in the company of Graham Scott of SAC, to look at suitability of sites for great yellow bumblebee and discuss management.  In contrast to the Open Day, the weather was terrible, but no excuse not to look at flowers.

I left Orkney on the afternoon ferry and headed to Bettyhill to join Paul Castle for a guided walk at the Farr Glebe bumblebee sanctuary.  The rain had abated and we had a beautiful evening with the few brave souls that had taken a gamble on the weather improving.  A great yellow bumblebee queen was busy collecting pollen, with perhaps the same individual returning within 20 minutes to gather more pollen.  After the walk, Paul and I looked at the Naverside area, where there is abundant kidney vetch this year, and also the peculiar legume, purple oxytropis.  We saw another great yellow bumblebee queen here.

Much of the remainder of the month was spent visiting sites to assess flower richness, suitability for Species Action Framework demonstration sites, or visiting farms. It was exciting to confirm that great yellow bumblebee was still present at Melvich, where they had been found for the first time last year by Paul.  The pollen & nectar mix plots on Caithness farms had now started to flower, and by the end of the month there were a number of records of great yellow bumblebees from the volunteers monitoring the sites.  There was an encouraging number of sightings of workers from the third week in July.  For me, a particular highlight was seeing my first great yellow bumblebees at Durness, with workers collecting pollen from red clover and a queen prospecting for a nest site at a stone wall.  In Caithness reports of workers included several away from the pollen & nectar mix plots.  This was the first chance we had to see which of the wildflowers were being used as pollen sources. Several of the verges were very flower rich, and the use of red clover and tufted vetch were not a surprise, but meadowsweet was.  The past two years of the Bumblebee Habitat Project has revolutionised our understanding of great yellow bumblebees in Caithness, with much cause for optimism.

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The Sunday Times Scottish University of the Year 2009/2010

The University of Stirling is a charity registered in Scotland, number SC 011159.

June 2010

June’s busy start continued right through the months.  There were a number of highlights, one of which was revisiting two flower-rich sites among the Dunnet Bay dunes, identified by Murdo Macdonald in 1999.  Queen great yellow bumblebees were present at both sites, which was fabulous.  At the south end of the dunes there is a good range of flower species, and the bees here were using red clover (see photo).  The other site is dominated by kidney vetch, and supports a healthy small blue colony (another UK BAP species).  The same evening we also held a training day for volunteers, starting at the Seadrift visitor centre (well worth a visit) and then moving out into the dunes.  Also in Caithness, the pollen and nectar seed mixes sown in May had germinated well, and the different components could be clearly picked out among the arable wildflowers. 

In Sutherland, there was an enthusiastic turn out for my talk in the village hall, and Donald Mitchell reported a great yellow bumblebee feeding on kidney vetch by the Durness visitor centre.  This was the first spring queen reported in the area since 2005, when one was seen at the same place (and two seen nearby) by a visiting entomologist.  An assessment of the diversity and abundance of flowers along the north Sutherland coast was particularly encouraging, especially in the Kyle of Tongue (a National Scenic Area dominated by the dramatic Ben Loyal).  There is a historic record from the Kyle (1974) and it is a crucial gap in the known modern distribution of great yellow bumblebee on the UK mainland.

The month finished in celebration of National Insect Week where my great yellow bumblebee work started two years ago, on the Inner Hebridean islands of Coll and Tiree.  These islands are the only places in Scotland where you can regularly see all three of Scotland’s priority bumblebee species: great yellow, moss carder (of the striking Hebridean form) and red-shanked carder. On Coll, we also now have the start of a bumblebee recording group, which is fantastic news.  There was an encouraging number of sightings of spring queen great yellow bumblebees, including one that had ventured into a local restaurant on Tiree (Ceabhar).  For the safari we had a glorious day at Balephetrish dunes - much better weather than when we were filmed in advance of the National Lottery Awards!  We saw several queen great yellow bumblebees, including ones collecting pollen (kidney vetch again) and also prospecting for nest sites.  We also found a Barbut’s cuckoo bumblebee Bombus barbutellus - present on Coll but this appears to be a ‘first’ for Tiree!  Across Gunna Sound, a queen buff-tailed bumblebee B. terrestris was a ‘first’ for Coll which seemed very out of place among the dunes. My ‘bumblebee safaris’ complemented talks by Darren Mann on the amazing oil beetles that had been discovered on Coll, and which rely on solitary bees for part of their life cycle.  I also had the great pleasure of meeting up with Donald MacKinnon of the Scottish Agricultural College, and visiting a number of crofts on Tiree that were considering applying to agri-environment schemes.  It is hard not to be enthralled by the islands, with basking sharks offshore and a rich diversity of birds (I came across a female corncrake and two young chicks on the roadside).  A long-tailed skua was a delight as it sailed along a beach on Tiree as I was busy counting red-shanked carder bee queens, and although there was some uncertainty as to whether I could leave the islands (the regular ferry was out of action), in the end it was probably for the best that I returned to Stirling!

 

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The Sunday Times Scottish University of the Year 2009/2010

The University of Stirling is a charity registered in Scotland, number SC 011159.